ss the building from
wall to wall, passing through holes in the walls, and were secured by
nuts on the outside. In this state they would have been sufficient to
have prevented the further separation of the walls by the weight of the
roof, but it was desirable to restore the walls to their original state
by drawing them together. This was effected in the following manner:
Alternate bars were heated by lamps fixed beneath them. They expanded,
and consequently the nuts, which were previously in contact with the
walls, were no longer so. The nuts were then screwed up so as to be
again in close contact with the walls. The lamps were withdrawn and the
bars allowed to cool. In cooling they gradually contracted and resumed
their former dimensions; consequently the nuts, pressing against the
walls, drew them together through a space equal to that through which
they had been screwed up. Meanwhile the intermediate bars were heated
and expanded, and the nuts screwed up as before. The lamps being again
withdrawn, they contracted in cooling, and the walls were further drawn
together. This process was continually repeated, until at length the
walls were restored to their perpendicular position. The gallery may
still be seen with the bars extending across it, and binding together
its walls.--_Philadelphia Record and Guide_.

LOSS OF POWER BY RADIATION OF HEAT.[3]

[Illustration: The Martyrs Column, Naples, Italy.]

To him who holds the purse and pays for the coal consumed, it is of
importance that between the energy of the burning fuel and the power
developed by the engine there should be the least possible loss. Every
unit of heat radiated by boiler-pipe, cylinder or heater is absolute
loss, and must come out of that purse. In an electrical plant this
matter is of great importance. There is less opportunity to have results
obscured. There is, proportionally, a large possible loss between the
coal on the grate and the far end of the cylinder, and this loss should
be reduced to the minimum. Is it not always the best economy to throw
away as little as possible, to save from waste _all_ that can be saved?
Is not the very _reason far being_, of the architect, the mechanical
engineer, in fact of every man who is paid for his advice and direction,
just this: that he shall bring to bear upon the subject, and impart to
his client honest knowledge concerning the various matters about which
he is consulted? That he shall keep abreast o